PAM Analysis
In Oscilloscope and Eye/Mask modes, you can perform electrical and optical measurements on Pulse Amplitude Modulation, PAM4, waveforms. Some measurements are available for PAM6 and PAM8. In Jitter Mode, some measurements can be made on PAM4 but not PAM6 or PAM8.
- Oscilloscope Mode measurements
- Eye/Mask Mode measurements
- Jitter and interference PAM4 measurements. Requires optional Advanced Eye Analysis feature.
Oscilloscope Mode PAM Waveforms
Eye Mode PAM Waveforms
Features
The following table shows some of the PAM4 features that are available. This is a partial listing to show the main tasks that you can perform.
| Feature | Support | ||
|---|---|---|---|
| Yes | Partial | No | |
| Compatible signal types | |||
| Single-ended | ♦ | ||
| Differential | ♦ | ||
| Common mode | ♦ | ||
| Eye mode | |||
| Dedicated PAM4 measurements (also measures NRZ signals) |
♦ | ||
| Measurements on Eye Meas tab | ♦ | ||
| Measurements on Adv Eye tab (Requires option 401) |
♦ | ||
| Mask testing | ♦ | ||
| Oscilloscope mode | |||
| Dedicated PAM4 level measurements | ♦ | ||
| Measurements on Time tab | ♦ | ||
| Measurements on Amplitude tab | ♦ | ||
| Jitter mode | ♦ | ||
| Simulated waveforms | ♦ | ||
| Math/Waveform signal processing functions | ♦ | ||
Autoscale and Signal-Type Detection
When an Auto Scale is performed, FlexDCA automatically identifies the signal type of all displayed channel, common mode, differential mode, and function waveforms. Signal types can be Unspecified, NRZ, PAM4, PAM6, or PAM8. In certain situations, a PAM waveform may not be able to be automatically identified. For example, this can happen when the waveform's eye is nearly closed. If this happens, open the Signal Types tab of the PAM-N Analysis Setup dialog and manually specify the signal type. These settings are linked to the settings in the local dialogs.
The source type of waveform memories and eye memories is not automatically detected during an Auto Scale, However, you can manually set the signal type by saving the waveform or color-grade gray-scale waveform to a file. This saves the signal type information within the file: unspecified, NRZ, PAM4, PAM6, or PAM8. If the file is then loaded into waveform or color-grade gray-scale memory, the signal type setting is loaded along with the data. You can always manually set the signal type in the Signal Types tab of the PAM-N Analysis Setup dialog.
For simulated modules, you can configure the simulated source waveform to be NRZ, PAM4, PAM6, or PAM8.
PAM4 measurements require FlexDCA version A.04.50 or later. PAM6 and PAM8 measurements require FlexDCA version A.08.30 or later.